Division of Biostatistics and Epidemiology, Department of Public Health, School of Public Health and Health Sciences, University of Massachusetts, 409 Arnold House, 715 North Pleasant Street, Amherst, MA 01003, USA.
BMC Womens Health. 2014 Apr 12;14:56. doi: 10.1186/1472-6874-14-56.
Moderate to severe premenstrual syndrome (PMS) affects 8-20 percent of premenopausal women. Previous studies suggest that high dietary vitamin D intake may reduce risk. However, vitamin D status is influenced by both dietary vitamin D intake and sunlight exposure and the association of vitamin D status with PMS remains unclear.
We assessed the relation of plasma 25-hydroxyvitamin D (25OHD), total calcium and parathyroid hormone levels with risk of PMS and specific menstrual symptoms in a case-control study nested within the prospective Nurses' Health Study II. Cases were 401 women free from PMS at baseline who developed PMS during follow-up (1991-2005). Controls were women not experiencing PMS (1991-2005), matched 1:1 with cases on age and other factors. Timed luteal phase blood samples were collected between 1996 and 1999 from cases and controls. We used conditional logistic regression to model the relation of 25OHD levels with risk of PMS and individual menstrual symptoms.
In analyses of all cases and controls, 25OHD levels were not associated with risk of PMS. However, results differed when the timing of blood collection vs. PMS diagnosis was considered. Among cases who had already been diagnosed with PMS at the time of blood collection (n = 279), 25OHD levels were positively associated with PMS, with each 10 nmol/L change in 25OHD associated with a 13% higher risk. Among cases who developed PMS after blood collection (n = 123), 25OHD levels were unrelated to risk of PMS overall, but inversely related to risk of specific menstrual symptoms. For example, each 10 nmol/L increase was associated with a significant 21% lower risk of breast tenderness (P = 0.02). Total calcium or parathyroid hormone levels were unrelated to PMS.
25OHD levels were not associated with overall risk of PMS. The positive association observed among women already experiencing PMS at the time of 25OHD measurement is likely due to confounding by indication related to use of dietary supplements to treat menstrual symptoms. Results from prospective analyses, which were less likely influenced by this bias, suggest that higher 25OHD levels may be inversely related to the development of specific menstrual symptoms.
中重度经前综合征（PMS）影响 8-20%的绝经前女性。先前的研究表明，高膳食维生素 D 摄入可能降低风险。然而，维生素 D 状态受膳食维生素 D 摄入和阳光暴露的影响，其与 PMS 的关系尚不清楚。
我们在前瞻性护士健康研究 II 中进行了一项巢式病例对照研究，评估了血浆 25-羟维生素 D（25OHD）、总钙和甲状旁腺激素水平与 PMS 风险和特定月经症状的关系。病例为 401 名基线时无 PMS 的女性，在随访期间（1991-2005 年）发生 PMS。对照组为 1991-2005 年无 PMS 的女性，按年龄和其他因素与病例 1:1 匹配。1996 年至 1999 年，从病例和对照组中采集了黄体期定时血样。我们使用条件逻辑回归模型来分析 25OHD 水平与 PMS 风险和个别月经症状的关系。
在所有病例和对照组的分析中，25OHD 水平与 PMS 风险无关。然而，当考虑采血时间与 PMS 诊断的关系时，结果有所不同。在已经在采血时被诊断为 PMS 的病例（n=279）中，25OHD 水平与 PMS 呈正相关，25OHD 每变化 10 nmol/L，风险增加 13%。在采血后发生 PMS 的病例（n=123）中，25OHD 水平与 PMS 总体风险无关，但与特定月经症状的风险呈负相关。例如，每增加 10 nmol/L，乳房触痛的风险显著降低 21%（P=0.02）。总钙或甲状旁腺激素水平与 PMS 无关。
25OHD 水平与 PMS 总体风险无关。在进行 25OHD 测量时已经患有 PMS 的女性中观察到的正相关可能是由于与使用膳食补充剂治疗月经症状相关的指示性偏倚所致。前瞻性分析的结果受这种偏倚的影响较小，表明较高的 25OHD 水平可能与特定月经症状的发生呈负相关。
